Convertible stadium



Oct. 3, 1961 J. w. WATERBURY 3,002,234

CONVERTIBLE STADIUM Filed Jan. 13, 1960 4 Sheets-Sheet 1 Oct. 3, 1961 J. w. WATERBURY CONVERTIBLE STADIUM 4 Sheets-Sheet 2 Filed Jan. 13, 1960 INVENTOR Jfi/A it! #4475590 BY M, W

ATTO 2' 5 Oct. 3, 1961 J. w. WATERBURY 3,002,234

CONVERTIBLE STADIUM Filed Jan. 13, 1960 4 Sheets-Sheet 3 Oct. 3, 1961 J. w. WATERBURY 3,002,234

CONVERTIBLE STADIUM Filed Jan. 13, 1960 4 Sheets-Sheet 4 3,002,234 CONVERTIBLE STADIUM John W. Waterbury, Irvington, N.Y., assignor to Praeger- Kavanagh-Waterbury, New York, N.Y., a partnership Filed Jan. 13, 1960, Ser. No. 2,202 Claims. (Cl. 1.126)

This invention relates to a stadium having one or more seating sections which are movable to change the overall configuration of the stadium and of the playing area within it to convert them from one usage to another, for example from baseball to football, and vice versa.

Many outdoor sports, such as football, soccer, lacrosse and others, require a rectangular playing area, and the most desirable locations for viewing such sports are adjacent the sidelines near midfield. Accordingly it is customary to concentrate the seating along the sidelines, with the sections of seats at opposite sides of the field extending parallel to the sidelines. In baseball, on the other hand, the playing field is generally pie-shaped, with an angle of 90 at the apex. The preferred arrangement of seating for baseball is therefore one in which the sections of seats at opposite sides of the playing field extend more or less perpendicularly to one another.

A stadium which is designed for football is not satisfactory for baseball, and vice versa, although, because of the great cost of constructing separate stadiums for each sport, stadiums designed for one of these two sports have sometimes necessarily been used for the other.

The present invention provides a stadium which can be converted from a seating arrangement adapted for football and other sports requiring a rectangular playing field to one adapted for baseball. This stadium has a movable seating section which is rotatable in a circular arc about an axis located in the central portion of the playing field, between two terminal positions, at one of which the rows of seats in the movable section are substantially parallel to those of a fixed seating section of generally corresponding size on the opposite side of the playing field, and at the other of which positions the rows of seats in these two sections extend more or less perpendicularly to one another. The outer edge of the movable seating section is supported on wheels rolling on a circular track which is concentric with the aforementioned axis, while the inner edge of the seating section is supported on removable pneumatic-tired wheel assemblies with built-in jacks for raising the seating section off the ground for movement. Since the latter wheel assemblies do not require tracks but roll directly over the ground, they may pass over portions of the playing field without the necessity of preparing the playing field for such movement or of restoring it to playing condition thereafter.

In each of its two terminal positions, the movable seating section rests on permanent foundation footings which are recessed slightly below ground level in shallow wells; when the seating section is moved so that these wells are on the playing field, they are covered over and sodded. The movable seating section is preferably divided into sub-sections which are moved independently of one another and which are secured together at each of the two terminal positions of the movable section. An outer, annular section of seats, completely encircling the perimeter of the stadium, may also be provided, with the inner edge of this outer section adjoining the outer edges of the two opposing sections previously described. This outer section may be provided with an inner vertical wall which is engaged by rollers at the outer edge of the movable inner section to augment the guidance of the latter. When the stadium is arranged for football or other sports requiring a rectangular playing field, its seating capacity may be readily increased by adding sections of auxiliary Fatented Get. 3, 1%61 seating at each end of the playing field, within the outer section.

In the drawings,

FIGURE 1 is a somewhat diagrammatic plan view of a stadium embodying features of the present invention, with the seating and the playing field arranged for baseball.

FIGURE 2 is a view similar to FIGURE 1 but showing the stadium set up for football.

FIGURE 3 is a diagrammatic fragmentary plan view of the stadium shown in FIGURES 1 and 2, showing particularly the sub-sectional construction of the movable seating section and illustrating the method of moving the sub-sections between their two alternative positions.

FIGURE 4 is a transverse sectional view through the central portion of the movable seating section.

FIGURE 5 is a fragmentary sectional view, at greatly enlarged scale, of the portion of the structure shown at the lower left-hand corner of FIGURE 4, particularly illustrating the structure at the lower end of the center vertical column at the outer edge of one of the movable seating sub-sections.

FIGURE 6 is a fragmentary elevational view of the structure shown in FIGURE 5, as viewed from the side which appears at the left in that figure.

FIGURE 7 is a view similar to FIGURE 6, but showing the structure for supporting the outer vertical columns of two adjacent sub-sections of the movable seating sectron.

FIGURE 8 is a fragmentary enlarged view of another part of the structure shown in FIGURE 4, particularly illustrating one of the foundation footings which support the movable seating section in each of its two terminal positions.

FIGURE 9 is a top plan view of one of the removable wheel assemblies which support the front edge of the movable seating section during movement.

FIGURE 10 is a cross-sectional view, at the scale of FIGURE 9, showing the front portion of one of the movable seating sub-sections with a removable wheel assembly in position thereon for movement of the subsection.

FIGURE 11 is a side-elevational view of one of the removable wheel assemblies.

The illustrative stadium shown in FIGURES 1 and 2 includes an outer seating section 20 having in plan an annular outline shape and extending completely around the perimeter of the stadium. This outer section 20' is provided with rows of seats 22 which extend generally parallel to the inner and outer edges of the sections that is, concentrically with the axis 21 of outer seating section 20, so that all of the seats face the central portion of the playing field. The rows 22 are vertically scaled-that is, the height of the seats increases in direct relation to their distance from the inner edge 20a of the section-to insure good visibility from all rows. Access to each of the rows 22 is provided by radially extending aisles 24, each of which has near its lower end a vomitory 26 communicating with a promenade (not shown) extending beneath the outer rows of seats.

Within the outer seating section 20 are two large inner seating sections 30 and 32, the outer edges 30a and 32a of which are curved in the form of circular arcs concentric with the axis 21 of the outer section 20, and which adjoin the inner edge 20a of the outer section. In the stadium illustrated, the inner edges 30b and 32b of the two inner sections 30 and 32 are straight and the rows of seats 34 in these sections extend parallel to one another and to their inner edges 30]: and 32b. The rows of seats are vertically scaled and aisles 36 and vomitories 38 are provided to permit ready access to all of the seats.

The maximum height of the inner sectionsthat is, the height of the top row at the widest point or center of the inner sections 30 and 32 is slightly less than the height of the first row of the outer section 20, so that these sections are, in practical effect, continuations of each other, both horizontally and vertically.

The inner seating section 30 is fixed in position while the opposed section 32 is movable in an arcuate path concentric with the axis 21, between the two terminal positions in which it is shown in FIGURES l and 2. In the position shown in FIGURE 1, the inner edge 32b of the movable section 32 is more or less perpendicular to the inner edge 30!) of the fixed inner section 30. For best visibility, an angle somewhat less than 90 between the inner edges of these two sections is desirable, with an angle in the range between 60 and 90 being preferable. When a baseball diamond is inscribed in the playing area between the seating sections, the foul lines 42 and 44 will extend at a shallow angle relative to the inner edges 30b and 32b of the inner seating sections 30 and 32; with the foul lines intersecting the inner seating sections at the far corners of the playing area, there will be sufiicient space behind and at either side of home plate 40 to permit chasing of pop fouls, etc. The adjacent ends of the inner seating sections 30 and 32 are spaced apart slightly and an additional seating section 46 fills the space between them, directly behind home plate 40. The rows of seats in this section 46 extend parallel to the inner edge of the section-that is, substantially perpendicular to a radius projected from the axis 21, so that the seats in this section face the center of the playing field. The arrangement shown not only places the seating sections as close to the playing area as possible, but orients the rows of seats so that there is excellent visibility from all portions of the stadium.

In FIGURE 2 the movable seating section 32b is shown rotated to the position for football and other sports requiring a rectangular playing area. In this position, the inner edge 32b of the movable section 32 is parallel to the inner edge 30b of the fixed inner section 30. Thus the playing area is generally rectangular and each of the rows of seats 34 in the sections 30 and 32 extends parallel to the sidelines 50 and 52 of the playing field for optimum visibility. To increase the seating capacity of the stadium for football, additional sections of temporary seats 54 and 56 may be installed behind the goal lines 58 and 60. The inner edges 54a and 56a of the temporary seating sections 54 and 56 shown in FIGURE 2 are curved in the form of circular arcs concentric with the axis 21, and the rows of seats therein extend generally parallel to the inner edges 54a and 56athat is, generally perpendicular to radii extending from the axis 21, so that all of the seats face the center of the playing field.

To illustrate how well the dimensions of the convertible stadium are adapted both for baseball and football, FIG- URE 1 and FIGURE 2 have been drawn to an approximate scale of A"=30'. In FIGURE 1, an outfield fence 47 has been installed a short distance inside the inner edge a of the outer seating section 20 to give a distance from home plate to deepest center field of 400 feet and foul line lengths of 325 feet from home plate to the fence 62 in both the right-field and left-field corners. This leaves a distance of approximately 75 feet from home plate to the inner edge of the seating section 46 directly behind it, and distances of at least 60 feet at either side of home plate to the nearest points along the inner edges b and 32b of the seating sections 30 and 32. With the football field inscribed within the playing area as shown in FIGURE 2, the football field having an overall length including the end zones of 120 yards or 360 feet, there remains a distance of approximately feet beyond each end zone to the inner edges 54a and 56a of the temporary seating sections 54 and 56.

Between the sidelines and 52 and the inner edges 30b and 32b of the seating sections 30 and 32, there is a dis tance of slightly less than 60 feet, which provides clearance for the safety of the players and spectators, as well as ample room for the players benches, etc. Those familiar with baseball and football will therefore appreciate that the proportions of the stadium are excellent for both sports. FIGURES 3-11 illustrate the means for supporting the movable seating section 32 to permit its movement between the two positions shown in FIG- URES 1 and 2. As may be seen in FIGURE 3, the movable section 32 may be divided into sub-sections 71, 72, 73, 74, 75, 76 and 77, which are separable from each other for individual movement but which are bolted together in the two terminal positions of the movable section 32 to form an effectively unitary structure. In the diagrammatic view of FIGURE 3, the rafters 80 and purlins 82 are shown in full lines and the bottom chord beams 84 are shown in broken lines. The particular arrangement of these structural members which is shown is, of course, merely illustrative.

FIGURE 4 shows a typical cross-sectional view through the inner movable section 32. As may be seen, the frame work is divided into five panels 81, 82, 83, 84 and 35 of equal horizontal dimensions, formed by top chords S6, 87, 88', $9 and 90, bottom chords 91, 92, 93, 94 and 95, vertical columns 96, 97, 98, 99 and 100, and diagonal bracing 101, 102, 103 and 104.

In each of its two terminal positions the movable section 32 is supported on concrete foundation footings 106 which are centered beneath the intermediate vertical columns 9'7 and of the movable seating section 32. Each of these footings is suitably supported, for example on four reinforced concrete pilings 108 which extend downwardly and symmetrically outwardly, preferably to bedrock.

As best shown in FIGURE 8, a removable column extension 110 is bolted to the lower end of each of the columns 97 and 100, and this extension 110 in turn rests upon a base member 112, which in turn is bolted to the concrete footing 106. The footing106 is located some distance below the level of the ground G, and the base members 112 are recessed within shallow concrete wells 114 whose upper ends are also slightly below ground level.

It will be understood that when the stadium is set up for baseball, as shown in FIGURE 1, the portions of the movable section 32 adjacent to the infield overlie an area which forms part of the playing field when the stadium is converted for football, as shown in FIGURE 2. Similarly, the portions of the movable section 32 which are near the right-hand goal line 60 in FIGURE 2 overlie an area which forms part of right field when the stadium is converted for baseball as shown in FIGURE 1.

When the movable section 32 is moved from one terminal position to the other, the column extensions 110 (FIGURE 8) are removed from the lower ends of the columns 97 and 100 and the upper end of each of the wells 114 which is exposed on the playing field is closed by a cover plate 116. The cover plate 116 is then covered over with dirt to grade level and sodded, as indicated in broken lines at S.

To permit movement of the movable seating section 32 between its two terminal positions, its outer edge 32a is supported by a series of rollers 120, which are shown in detail in FIGURES S, 6 and 7. As may be seen in these figures, the rollers 120 are rotatably supported on axles 122 at the lower ends of forks 124 which project downwardly at spaced points along the lower face of a transverse beam 126 which is secured at the lower end of each of the vertical columns 96' at the outer edge of the movable section 32. FIGURE 6 shows the arrangement of rollers at the lower end of one of the intermediate vertical columns 96 of one of the subsections, while FIGURE 7 ShOWs the arrangement of rollers at the lower ends of the cutside vertical columns 96 at the rear corners of two of the adjacent sub-sections. The intermediate columns 96, as shown in FIGURE 6, are provided with four wheels 120 and the elongated beam 126 on which they are supported is braced relative to the column 96 by triangular fillets 128. As may be seen in FIGURE 7, the shorter transverse beams 126' on the adjacent outside vertical columns 96 are each provided with only two Wheels 120. The adjacent sub-sections are secured together by a short piece of channel 130 which is bolted to the outer faces of the adjacent vertical columns 96. This piece of channel is, of course, removed to permit the subsections to be moved separately from one terminal position of the movable section 32 to another, as previously described.

The wheels 122 ride upon a steel rail 132 which extends along the upper surface of a footing 134 which extends inwardly from the base of a vertical concrete wall 136 (see also FIGURES 4 and 5). This vertical wall 136 forms the lower portion of the inner edge of the outer seating section 20, and the inner surface of the wall 136, the footing 134 and the rail 132 are all curved in the form of circular arcs concentric with the axis 21 (FIG- URES 1 and 2). As best shown in FIGURE 5, the wheels 12.0 are flanged and engage the rail 132 at each side to guide the movements of the sub-sections of the movable seating section 32. To provide further guidance, the vertical columns 36 carry rollers 138 which are rotatably mounted in brackets 14% secured to the outer faces of the vertical columns (see also FIGURES 6 and 7) and these rollers 138 engage the inner face of the vertical wall 136 to prevent the wheels 120 from being derailed from the rail 132 in a direction remote from the playing field, and also to aid in preventing crabbing movement of the sub-sections.

The movable seating sub-sections are supported at their inner edges for movement between their two terminal positions by removable wheel assemblies, of which one is shown in FIGURES 9, and 11. These three figures illustrate one of the heavier wheel assemblies 146 which is used to support the central portion of the inner edge of each movable seating sub-section (see also FIGURE 3). These heavier wheel assemblies are each provided with eight pneumatically-tired wheels 150 rotatably mounted on two axles 152. The lighter wheel assemblies 148 (FIGURE 3) which are used to support the two front corners of the respective movable seating sub-sections are similar but somewhat lighter in construction and are provided with only four wheels.

As shown in FIGURE ll, the two axles 152 of the wheel assembly 146 project transversely of a longitudinally extending frame 154 which has an underslung central portion 154a on which is mounted a hydraulic jack 156. Supported on this jack 156 is a guide beam 158 which is vertically movable relative to the frame 154 but is held parallel thereto by lugs 159 which extend downwardly from the lower ilange of the guide beam 158 at opposite sides of the frame 154. The guide beam 158 is pivotally attached to the underside of an outrigger beam 160 by a bolt 161. As shown in FIGURES 9 and 10, the remote end of the outrigger beam 160 is adapted to rest upon one of the steps 162 of the seating sub-section, this step 162 being especially reinforced by additional purlins 164 and 166 and columns 168. The inner edge 32b of the movable seating section 32 is suspended from the intermediate portion of the outrigger 161 by tie rods 1'72 which extend on opposite sides of the guard rail 170 at the inner edge 32b. The lower ends of these tie rods 172 are bolted to a plate 174 which extends beneath the beam 175 at the inner edge 3212, while their upper ends are bolted to a channel 1'7 6 which extends across the top of the outrigger beam 160. It will thus be seen that when the lower ends of the columns 97 and 100 are unbolted from the extension columns 113 (FIGURES 4 and 8) the jacks 156 (FIGURE 11) of the wheel assemblies are simultaneously extended, the guide beam 158 and the outrigger 160 will be raised, lifting the inner edge 32b of the movable seating sub-section to lift the lower ends of the columns 97 and 160 off the extension columns 110. Thus, the movable seating sub-section will be supported entirely on the wheels (FIGURE 4) at its outer edge and on the three removable wheel assemblies 146 and 148 at its inner edge.

As diagrammatically shown in FIGURE 3, one illustrative method of moving the seating sub-sections between their two terminal positions is by means of a pair of tractors 180 and 182. The tractor 131i is shown attached by means of cables 184 and 186 to the points 188 and 199 (see also FIGURE 4) on each sub-section, and the tractor 182 is attached by means of a towline 192 (FIGURE 3) to a coupling 194 (FIGURES 9-11) at the forward end of the guide beam 158 of the heavy wheel assembly which is located at the center of the inner edge of each sub-section. It will be obvious that as the subsections near their final position, the tractor 133 will reach a point where it cannot go farther without running into the seating sections ahead of it. At this point, the tractor is moved around to the trailing side of the seating sub-section and used to push the sub-section the remaining distance to its final position against the seating subsection ahead of it.

As can best be understood by reference to FIGURE 3, the angle between the outrigger 160 and the guide beam 158 of each of the several wheel assemblies varies in accordance with the location of the wheel assembly relative to the movable seating section 32 as a whole. For example, in the wheel assembly in the position C which is located at the exact center of the movable section 32, the guide beam 158 extends substantially perpendicular to the outrigger 160, while in the position E1 at the upper end of the seating section 32 these two members extend at an oblique angle relative to one another. It will be understood that at each support position along the seating section, the outrigger 160 extends perpendicular to the inner edge 32b of the seating section while the guide beam 158 extends perpendicular to a radius extending from the axis 21 (FIGURES l and 2). The pivotal arrangement of the guide beam 158 relative to the outrigger 160 permits variation of these angles as required; a series of holes 204 (FIGURE 9) are provided in the adjacent flanges of the guide beam 158 and outrigger 160, and a pin 206 (FIGURE 11) extends through selected pairs of these holes tolock the two members at the desired angle.

From an inspection of FIGURE 3 it will be apparent that in the lower half of the movable seating section 32, for example at the position E2 at the lower end, the angularity of the guide beam 158 and outrigger 160 is such that the wheel assemblies must be pushed rather than pulled. This is done by a rigid bar 210 which connects the wheel assembly to the tractor 182. The

pneumatic-tired wheels of the wheel assemblies are adapted to roll directly over the ground, so that they may pass over portions of the playing field, without the necessity of rails which have to be laid down and picked up or covered and uncovered in order to move the seating section 32.

From the foregoing description, it will be appreciated that the present invention provides a stadium construction which is convertible from a seating arrangement suitable for football to one suitable for baseball, in an eflicient and practical manner. However, it should be emphasized that the particular embodiment of the invention which is described herein and described in the accompanying drawings is intended as merely illustrative of the principles of the invention rather than as restrictive of the scope thereof. By way of example, the outer seating section 20 may be dispensed with. Moreover, the outline shape of the inner seating sections 30 and 32 may be altered as desired, as may the arrangement of rows of seating in these sections. The movable seating sections may include more than one tier of seats, and any or all portions of either the fixed or movable sections, or both, may be covered with a roof. It is therefore intended that the coverage of this patent is not to be limited to the specific illustrative embodiment disclosed herein, but only by the appended claims.

I claim:

1. A stadium comprising two opposed seating sections each having a plurality of tiered seats, said seating sections having their inner edges spaced apart, a playing field between said inner edges, a horizontal track extending entirely outside of said playing field and movably interengaging and supporting the outer edge of one of said seating sections, said track being curved in the form of a circular arc concentric with a vertical axis located in e the central portion of said playing field and being of sufficient length to permit endwise ancuate movement of the one said seating section from a point where the inner edges of the two sections are substantially parallel to a point where they are generally perpendicular, and a plurality of wheel assemblies removably supporting at spaced points the inner edge of the movable seating section.

2. A stadium comprising two opposed seating sections each having a plurality of tiered seats, said seating sections having their inner edges spaced apart, a playing field between said inner edges, one of said seating sec tions being divisible into subsections which fit side-byside in substantial contiguity, a horizontal track extending entirely outside of said playing field and movably interengaging and supporting the outer edges of said subsections, said track being curved in the form of a circular arc concentric with a vertical axis located in the central portion of said playing field and being of sufiicient length to permit movement of said subsections between positions at which said inner edges of the two sections are substantially parallel and positions at which they are generally perpendicular, and a plurality of wheel assemblies removably supporting at spaced points the inner edges of each of said subsections, said wheel assemblies having wheels for rolling directly upon the ground.

3. A stadium comprising two opposed seating sections each having a plurality of tiered seats, said seating sections having their inner edges spaced apart, a playing field between said inner edges, a plurality of wheels mounted at spaced positions along the bottom of the outer edge of one of said seating sections for rotation about horizontal axes which are generally radial with respect to a common axis in the central portion of said playing field, a horizontal track extending entirely outside of said playing field and supporting said wheels, said track being curved in the form of a circular arc concentric with said axis and being of sufiicient length to permit movement of said section between positions at which said inner edges of the two sections are substantially parallel and positions at which they are generally perpendicular, and a plurality of removable wheel assemblies supporting at spaced points the inner edge of the movable seating section, said wheel assemblies having wheels for rolling directly on the ground.

4. A stadium comprising two opposed seating sections each having a plurality of tiered seats, said seating sections having their inner edges spaced apart, a playing field between said inner edges, a plurality of wheels mounted at spaced positions along the bottom of the outer edge of one of said seating sections for rotation about horizontal axes which are generally radial with respect to a common axis in the central portion of said playing field,

, a horizontal track extending entirely outside of said playing field and supporting said wheels, said track being curved in the form of a circular arc concentric with said axis and being of sufficient length to permit movement of said section between positions at which said inner edges of the two sections are substantially parallel and positions at which they are generally perpendicular, a plurality of removable wheel assemblies supporting at spaced points the inner edge of the movable seating section, said wheel assemblies having wheels for rolling directly on the ground, and jacks for raising the inner edge of said movable seating section clear of the ground for movement on said wheel assemblies.

5. A stadium comprising two opposed seating sections each having a plurality of tiered seats, said seating sections having their inner edges spaced apart, a playing field between said inner edges, a plurality of wheels mounted at spaced positions along the bottom of the outer edge of one of said seating sections for rotation about horizontal axes which are generally radial with respect to a common axis in the central portion of said playing field, a horizontal track extending entirely outside of said playing field and supporting said wheels, said track being curved in the form of a circular arc concentric with said axis and being of sufficient length to permit movement of said section between positions at which said inner edges of the two sections are substantially parallel and positions at which they are generally perpendicular, a plurality of removable wheel assemblies each comprising a frame having pneumatic-tired wheels rotatably mounted at its four corners, and a jack projecting upwardly from the center of each of said wheel assemblies and removably supporting the front edge of said movable seating section for movement as described.

6. A stadium comprising two opposed seating sections each having a plurality of tiered seats, said seating sections having their inner edges spaced apart, a playing field between said inner edges, a plurality of wheels mounted at spaced positions along the bottom of the outer edge of one of said seating sections for rotation about horizontal axes which are generally radial with respect to a common axis in the central portion of said playing field, a horizontal track extending entirely outside of said playing field and supporting said wheels, said track being curved in the form of a circular arc concentric with said axis and being of sufiicient length to permit movement of said section between positions at which said inner edges of the two sections are substantially parallel and positions at which they are generally perpendicular, a plurality of removable wheel assemblies each comprising a frame having pneumatic-tired wheels rotatably mounted at its four corners, an outrigger extending horizontally from said frame with its remote end positioned to rest upon a horizontal step of said movable seating section at a distance from its inner edge, tie means for securing the inner edge of said movable seating section to the portion of said outrigger immediately above it, and a jack mounted at the center of said frame removably supporting the adjacent end of said outrigger and thereby the inner edge of said movable seating section for movement as described.

7. A stadium comprising at least two opposed seating sections having generally straight inner edges spaced apart to define between them a playing field, and each of said seating sections having a plurality of tiered rows of seats each extending generally parallel to said inner edges, a plurality of wheels mounted at spaced positions along the bottom of the outer edge of one of said seating sections for rotation about horizontal axes which are generally radial with respect to a common axis in the central portion of said playing field, a horizontal track extending entirely outside of said playing field and supporting said Wheels, said track being curved in the form of a circular arc concentric with said axis and being of sufiicient length to permit movement of said subsections between positions at which said inner edges of the two sections are substantially parallel and positions at which they are generally perpendicular, a plurality of removable wheel assemblies each comprising a frame having pneumatic tired wheels rotatably mounted at its four corners, a jack extending upwardly from the center of said frame, a horizontally extending guide beam centrally supported by said jack, an outrigger secured to said guide beam and projecting horizontally therefrom with its remote end removably bearing upon a preselected portion of a horizontal step of said movable seating section at a distance from its inner edge, the angles between the Outriggers and guide beams of the several wheel assemblies differing so that when each is in place on said movable seating section the outriggers are generally perpendicular to its inner edge, while the guide beams are each perpendicular to radii projecting from said axis, and tie means removably securing the inner edge of said movable seating section to the portion of said outrigger immediately above it, whereby extending said jacks will raise the inner edge of said movable seating section and permit towing of said wheel assemblies by tow 'lines attached to the forward ends of certain of said guide beams, for movement of said movable seating section as described.

8. A stadium comprising two opposed inner seating sections each having a plurality of tiered rows of seats, said inner seating sections having their inner edges spaced apart to define between them a playing field, and at least one of said inner seating sections having its outer edge curved in the form of a circular are about an axis located in the central portion of said playing field, a plurality of wheels mounted at spaced positions along the outer edge of the one said seating section for rotation about horizontal axes which are generally radial with respect to said axis, an outer seating section having an inner edge located substantially contiguous with the outer edge of said movable inner seating section, a horizontal track extending adjacent the base of the inner edge of said outer section and interengaging and supporting said wheels, said inner edge of said outer section and said track each being curved in the form of a circular arc concentric with said axis, and each being of sufiicient length to permit movement of said movable seating section from a position at which the inner edges of the two inner seating sections are substantially parallel to a position at which they are generally perpendicular, and a plurality of wheel assemblies for supporting at spaced points the inner edges of each of said subsections, said wheel assemblies having wheels for rolling directly upon the ground.

9. A stadium comprising two opposed inner seating sections each having a plurality of tiered rows of seats, said inner seating section having their inner edges spaced apart to define between them a playing field, and at least one of said inner seating sections having its outer edge curved in the form of a circular arc about an axis located in the central portion of said playing field, a plurality of wheels mounted at spaced positions along the outer edge of the one said seating section for rotation about horizontal axes which are generally radial with respect to said axis, an outer seating section having in plan an annular outline shape with an angular extent of at least approximately 270, and having its inner edge substantially contiguous with the outer edge of said inner sections, a horizontal track extending adjacent the base of the inner edge of said outer section and interengaging and supporting said wheels, said inner edge of said outer section and said track each being curved in the form of a circular arc concentric with said axis, rollers mounted at the outer edge of said movable inner section for rotation about vertical axes, a bearing surface at the inner-edge of said outer section arcuately curved about said axis and engaging said rollers to guide the movement of said movable inner section, said track and said bearing surface being of suflicient angular extent to permit movement of said movable seating section from a position at which the inner edges of the two inner seating sections are substantially parallel to a position at which they are generally perpendicular, and a plurality of wheel assemblies for supporting at spaced points the inner edge of the movable seating section, said wheel assemblies having wheels for rolling directly upon the ground.

10. A stadium comprising two opposed inner seating sections each having a plurality of tiered rows of seats, said inner seating sections having their inner edges spaced apart to define between them a playing field, and at least one of said inner seating sections having its outer edge curved in the form of a circular are about an axis located in the central portion of said playing field, a plurality of wheels mounted at spaced positions along the outer edge of the one said seating section for rotation about horizontal axes which are generally radial with respect to said axis, an outer seating section having in plan an annular outline shape with its inner edge substantially contiguous with the outer edges of said inner sections, and having at its inner edge a generally vertical concrete wall with a continuous footing extending from the inner side of the base thereof, a rail mounted on said footing and engaging and supporting said wheels, said wall and said rail each being curved in the shape of a circular are concentric with said axis, and each being of suflicient length to permit movement of said moveable seating section from a position at which the inner edges of the two inner seating sections are substantially parallel to a position at which they are generally perpendicular, rollers mounted at the outer edge of the movable seating section for engaging said wall to guide the movement of said movable seating section, and a plurality of removable wheel assemblies for supporting at spaced points the inner edge of said movable seating section, said wheel assemblies having wheels for rolling directly on the ground.

References Cited in the file of this patent UNITED STATES PATENTS 1,433,547 Hadden Oct. 31, 1922 

